The larvae of three species of Diabrotica beetles are among the most serious insect pests of corn in the United States. These three species include the western corn rootworm, Diabrotica virgifera virgifera LeConte, the northern corn rootworm, Diabrotica barberi Smith and Lawrence, and the southern corn rootworm, Diabrotica undecimpunctata howardi Barber. More insecticide is used for the control of Diabrotica spp. than for any other pest of corn, and the total acreage treated is greater than for any other insect pest in the United States.
Diabrotica larvae emerge in the spring from overwintering eggs laid in the soil the previous fall. After hatching, the neonate larvae move through the soil and locate suitable host roots. There is increasing evidence that host location is facilitated by volatile semiochemicals (chemicals that are used for communication) produced by the corn plant. Cryogenic collections of volatile compounds, including carbon dioxide, that emanate from germinating corn seeds are known to be attractive to rootworm larvae. (Hibbard et al., J. Chem. Ecology, 14:1523 to 1539, 1988).
It has been found that 6-methoxy-2-benzoxazolinone (6-MBOA) is also attractive to corn rootworm larvae and can be used in the management of corn rootworm damage to corn either alone or in combination with other more commonly used insecticides.